Method and means for cutting and forming sheet metal



' Jan. 19, 1943. c. c. MISFELDT 2,303,993

METHOD AND mums FOR CUTTING AND FORMING SHEET MET-AL Filed May 28, 19405 Sheets-Sheet 1 C H m:

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' INVENTORI TTORNE Y.

Jan. 19, 1943. c. c. MISFELDT METHOD AND MEANS FOR CUTTING AND FORMINGSHEET METAL Filed May 28, 1940 3 Sheets-Sheet 2 CHAR: E5 C 4051 5407,

- I INVENTOR;

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A TTORNE Y.

Jan. 19, 1943. c. c. MISFELDT 2,303,998

.METHOD AND MEANS FOR CUTTING AND FORMING SHEET METAL Filed May 28, 19403 Sheets-Sheet 5 11v VENTOR,

. A TTORNEY.

Patented Jan. 19, 1943 UNITED STATES PATENT oFFlcE" Mn'rnon AND amassron ou'r'rmc AND some seem METAL Charles 0. Misfeldt, Glendale, CaliL,miner to Douglas Aircraft Company, Inc, Santa Monica, Calif., acorporation of Delaware Application May 28, 1940, Serial No. 337,623

8 Claims. '(Cl. 113-42),

the invention being intended principally for the.

forming of parts from sheet metal but "not being limited thereto. Thepresent invention is an improvement over the processv known in theaircraft manufacturing industry as the Guerin process and disclosed inthe patents to Henry E. Guerin Nos. 2,055,077, and 2,133,445, whereinsheet metal is cut and formed by use of simple forming and cuttingblocksagainst which the sheet metalis forced by a body ofelastic'conformable material, such as a rubber compound, for example.

An object of-the present invention is to provide a process for makingparts having greater depth of draw in conjunction with relatively sharpcontour, than is possible in prior art proc-' esses with a givencharacter and thickness of sheet material.

In a process, where a portion of the sheet metal is forced down into aspace adjacent to an edge or a shoulder of a forming block, the onlyextemalcontrol on the movement of this portion of the sheet prior toengagement with a wall of the forming block is that which is exerted bythe'rubber material in contact with the upper surface of the sheetportion. The rubber, due to its plastic and/or fluid-likecharacteristics, may move in all directions. Therefore, it does notexercise an independent control of the movement of the sheet toward thefaces of the forming block, but merely cooperates with other factorsinvolved in the process, one of which is flow of the metal in directionsand to degrees which may depend upon a number of considerations, in-

cluding contour of the shoulder of the forming An important object ofthe present invention is to provide mean in a process of the generalcharacter described for accomplishing a better control of the flow ofthe sheet metal, to cause metal to flow from salvage portions of thesheet, to avoid thinning of the metal due to the forming action, toconcentrate the crystallizing effects in the metal structure to areasconstituting salvage which is removed from the iinished part, and toaccomplish a deep drawing of contoured flanges and means withoutwrinkling of the sheet.

It is an object of the invention to provide a method and means wherebyplate members having flanges along straight and curved or contourededges thereof may be formed with such flanges in a single operationwithout wrinkling of the sheet from which the plate members are formed.

It is an object of the invention to provide a method and apparatuswherein flanges are formed along contoured edges by drawing the metalcausing it to flow to such extent that wrinkling is avoided, therebyeliminating the need for cut-outs in the flanges to compensate forexcess metal.

It is a further object of the invention to provide a method andapparatus for drawing, forming, and cutting parts from sheet metalwherein the need for hand finishing is minimized; wherein themanufacturing time and number of operations are materially reduced;wherein thereis greater economy in the use of sheet metal for the reasonthat there is less scrap; wherein the metal entering into certainflanges are flrst drawn and then cut or trimmed as a substantiallycontinuous operation; wherein less space is required and wherein thecutting blades are easily applied to the forming block; and wherein adesired constraining effect or restraint is put on certain portions ofthe sheet so that the desired drawing eil'ect may be produced onselected portions in accordance with the characteristics of the formingblock on which the part is made and the extent to which the inetal mustbe caused to flow to accomplish a desired effect.

It is a further object of the invention to provide a method andapparatus wherein the sheet which is to be drawn, formed, and cut isengaged on one side thereof by the elastic conformable material and isengaged on its other side by spaced means disposed so as to form arecess therebetween in which a cutting or parting element is placed, atleast one of the engaging means restraining the portion of the sheetbetween the engaging means from free movement so that the pressure andmovement of the material will flow and bend the portion of the sheetbetween the engaging means into the recess wherein such drawn portion ofthe sheet will be parted by engagement with the parting means.

Herein I employ the term flow, with reference to the drawing of thesheet metal, to mean change in position of the metal without materialchange in the thickness and include stretching or shrinking, or both ofthese effects.

It is an object of the invention to provide a method and apparatus ofthe above character wherein the sheet metal entering into flange or cupportions of an article is moved under pressure applied through the useof a body of elastic conformable material to a position intermediate itsinitial position and its final position in en-' gagement with theforming block, is then severed along established lines, and is thenfurther moved toward its final position.

It is a further object of the invention to provide a method of thecharacter set forth in the preceding paragraph wherein portions of asheet lying in projecting relation to a forming body are in asubstantially continuous operation consecutively and/or alternatelymoved and out under pressure exerted by a body of elastic conformablematerial, until such part finally reaches its position of engagementwith cooperating areas of the forming member.

This application is a continuation-in-part of I my pending applicationSerial No. 254,657, flied February 4, 1939, for Method and apparatus fordrawing, forming, and cutting sheet metal.

Further objects and advantages of the invention will be brought out inthe following part of the specification.

Referring to the drawings which trative purposes only:

Fig. 1 is a perspective view of an article formed from sheet metal byuse of the invention.

Fig. 2 is a plan view of a drawing, forming, and cutting die usable informing the article shown in Fi 1.

Fig. 3 is a cross-section taken as indicated by the line 3-3 of Fig. 2and showing above the die a body of yieldable conformable material.

Fig. 4 is an enlarged fragmentary section taken on a plane representedby the line 4-4 of Fig. 2, showing the flrst operation after placing ofthe cooperating parts, including the sheet: to be formed, in the press.

Fig. 5 is a fragmentary section similar to Fig. 4, showing a subsequentoperation, with the sheet in position to be out after drawing andforming thereof.

Fig. 6 is an enlarged fragmentary section taken on a plane representedby the line 66 of Fig. 2.

Fig. 7 is a fragmentary perspective view looking toward a corner of theforming block and the corner cutting member thereat.

Fig. 8 is another perspective view of the corner of the forming blockshown in Fig. '7 but taken at a different angle.

Fig. 9 is a plan view of a part produced by an alternative form of myinvention.

Fig. 10 is a plan view of the forming block employed in the making ofthe part shown in Fig. 9.

Fig. 11 is an enlarged fragmentary sectional view taken as indicated bythe line lI-ll of Fig. 10, and illustrating the consecutive steps in theformation of the part disclosed in Fig. 9.

The article ID shown in Fig. 1 may be referred to in accordance with theterminology of the metal working trades as a metal stamping for thereason that it is made from a flat sheet of metal and is drawn, formed,and cut so as to provide a top wall or plate portion ll, having a curvededge I 2 with a flange [3 extending downwardly from the edge I2, andessentially traight edges are for illus- I4 and I5 disposed at rightangles to each other and being joined by a rounded corner, there being'a continuous flange l'l extending down from the edges l4 and I5 and thecorner II.

In the stamping of a part,'such' as the article ill, from sheet metal,the portions ofthe sheet which are to form flanges extending downwardfrom contoured edges must be drawn during the flanging operation toprevent wrinkling of the metal. Such drawing of the metal is ordinarilyaccomplished in standard metal stamping processes by use of companionpunch and die parts. In the present invention this same result offorming flanges along contoured edges of an article formed from sheetmetal, is accomplished by use of relatively inexpensive forming blocks,avoiding the use of expensive companion punch and die parts,the'movement of the sheet metal during the forming operation beingaccomplished by the application of a body of elastic conformablematerial, preferably a rubber compound, for the reason that rubber,although it will readily conform itself to the exterior of the formingblock, is of such resilient character as to return substantially to itsoriginal shape, and for the further reason that rubber compound may bereadily obtained in cured state wherein it will not adhere to thesurface of the formed article but will readily disengage itselftherefrom when pressure is removed.

For the'article ill I provide a forming block 22 having a top face 23, acurved side face 3|, and straight side faces 32 and 33 which aredisposed in perpendicular planes and are joined by a rounded corner 34.The side face 3| is merged with the top face 23 by a rounded shoulder35, and the side faces 32 and 33 and the comer 34 are merged with thetop face 23 by a rounded shoulder 36. Guide pins 30 are projected fromthe forming block 22 to provide guides for the sheet which is placed onthe forming block prior to the drawing, forming, and cutting of thearticle ID from the sheet.

It is a feature of the invention to place adjacent a contoured side faceof the forming block 22 a restraining surface against which a projectingportion of the metal sheet may be clamped in a manner to hold or retardthe movement of this extended portion toward the contoured side face sothat as the metal is shaped down around the contoured 'side face it willflow and be drawn to the desired shape. In most instances suchrestraining surface is advantageously provided by use of restrainingblocks spaced from the forming block. As shown in Fig. 2, I place acurved restraining block 40 in parallel and spaced relation to thecontoured side face 3! and adjacent the comer 34 I place an L-shapedrestraining block 4|, each of the restraining blocks 40 and 4| having atop face 42 and a side face 43 merging with the top face through arounded shoulder 44. A space or recess 45 exists between the side faceof the restraining member 40 and the side face 3| of the forming block22, and a space 46 exists between the side face 43 of the restrainingmember 4| and portions of said faces 32 and 33 adjacent the corner 34.Cutting means are provided adjacent the side face of the forming block22 in planes below the top face 23 of the forming block, the positionsof these cutting means being determined by the width of the flanges l3and I1. Such cutting means are shown as cutting edges 48 disposed onupwardly faced knife elements 49 which may be the upwardly turned lipsaround the edges of a plate 50 which is placed between the forming block22 and a supporting plate to which the forming block 22, the plate 50,and the restraining members 40 and 4| may be secured. Above the support5| a movable head 53 is supported, this head having down turned flanges54 defining a space in which a body of elastic conformable material 55is held, the inner faces of the walls 54 being spaced so that they willpass down around the peripheral edges of the supporting plate 5| whenthe head 53 is lowered under pressure.

The drawing, forming, and cutting'operation is performed as follows: Asheet of metal, or other sheet material of similar physicalcharacteristics, is placed as shown by dotted lines 50 in Fig. 3, inposition resting across the forming block 22, this sheet 50 beingprovided with openings to receive the guide pins 30 so that the sheetwill be positioned with edged portions 6| projecting beyond the limitsof the forming block 22 and extending a suitable distance over therestraining members 40 and 4|. The head 53 is then lowered underpressure to bring the body 55 into engagement with the sheet 60 to forcethe same down against the forming block 22, against the restrainingmembers 40 and 4| and likewise toward the surface portions 15 of thesupporting plate 5| between the ends of the restraining members 40 and4|, with the result that the article II] is completely drawn, formed,and cut and remains in completed form. as shown in full lines in Fig. 3.when the head 53 is again raised.

The shaping of the metal from its initial fiat form to finished form isbelieved to take place as follows: As shown in Fig. 4 the elasticconformable body 55 forces the sheet down so that it will be grippedbetween the body 55 and the forming block 22 and so that the projectingedge portions 5| will be moved downward to engage and be gripped againstthe upper faces .42 of the restraining members. For the purpose ofillustration, Fig. 4 shows only one of the restraining members, namely,member 4 i, it being understood that the efiects illustrated therein areattained also between the restraining member 40 and the cooperating edgeof the forming block 22. The upper face 42 of the restraining member 4|is shown in a plane below the upper face 23 of th forming block 22. Thediflerence in height of the faces 23 and 42 may be 'varied in accordancewith the amount of drawing required in shaping the sheet metal aroundthe forming block. Also. the area of engagement of the sheet 60 with theupper face 42 of the forming block 4|, and also the preparation of theface 42 for interengagement with the sheet 5!), may be varied inaccordance with the requirements of each particular article as towhether the edge of the sheet is to be gripped tightly against movementtoward the forming block or is to be permitted more or less slidingmovement toward the forming block during the forming operation, whichconditions in turn depend upon-the extent to which the metal is to bedrawn, the depth of draw, the flow of the metal to correspond to adesired contour, and the gauge and type of metal to be drawn un- I derconditions such as specified in the foregoing.

As the downward movement of the head 53 continues, the elasticconformable material 55, as

shown in Fig. 5, will continue to grip the sheet 50 against the upperface 23 of the member 22 and by pressure of the projecting edge portion5| against the upper face of the restraining block will restrain thisprojecting edge portion iii to the extent desired. For example, the edgeportion may be in some instances gripped against any movementwhatsoever, but in general prac-. tice the edge portion of the sheet isailowed'to slide on the upper face of the restraining block to an extentsuch as indicated in the following description.

The tendency of the material 55 to flow down into the recess 46 between.the forming block 22 and the restraining member 4| will force thatportion ill of the sheet 60 which is stretched across the space 45downward into the space, thereby causing such intervening portion 10 totake the form of a U-shaped channel depending from the rounded shoulders35 and 44. Inasmuch as the sheet 50 is positively gripped on themember22 by reason of a large constraining surface and the fact that the pins30 hold that portion of the sheet from moving, the projecting edgeportion 5| will slip relative to the member 4| as the drawin and formingaction takes place, until such time as the sheet portion 5| rounds thecorner 44 of the member 4| and will be no longer able to slip since therestraint is now in two planes.

The arangement of the restraining members and the cutting edge is suchthat the sheet will come in contact with the cutting edge almostsimultaneously with the gripping of the sheet on the member 4| andtherefore the metal will begin stretching in that portion of the sheetbetween the corner 44 and the cutting edge 48 as the material 55continues to come down into the recess 45. This stretching will continueuntil the channel formed by the intervening metal 10 isparted along aline defined by the cutting edge 48, thereby severing the metal portionHifrom the flange portion I] which is to enter into the flanged productIn, whereupon the pressure and movement of the elastic conformablematerial 55 will immediately force the flange l1 against the side face33, and the remainder of the projecting sheet down along the side face43 of the restraining member 4| as shown in Fig. 3.

In some practices of the invention the surfaces 42 of the restrainingmembers 40 and 4| may be essentially smooth and flat, but where greaterrestraining effect is required, these surfaces 42 may be prepared bybeing roughened or contoured so as to produce a complete or partialinterengagement between the restraining members 40 and 4| and the sheetmetal. As an example of this I have shown a bead 25 on the upper surfaceof the restraining member 4|, such a bead serving to control slidingmovement of the edge portion of the sheet 5|! relative to the space 42and also prevent wrinkling of the edge portion 5| of the sheet.

From the foregoing it will be perceived that the flange I1 is nearlycompletely drawn and formed before it is severed from the peripheralportion of the original sheet 50. The cutting edge 48 may be spaced atsuch distance from the side face 33 of the forming block 22 that theparting of the sheet will take place after the portion thereof which isto enter into the flange of the finished part is drawn to such an extentthat it will not wrinkle during completion of the forming operation.Likewise, the spacing of the cutting edge 48 from the face 33 of theforming block 22 exercises a control .over the thickness of theresulting flange since in'the carrying out of the process it is notnecessary to continue the stretching of the intervening portion 10 ofthe sheet until the flange portion l1 comes into engagement with theside face 33. Also, a'shrinking and consequent thickening of the flangeportion I1 may in some instances be accomplished after the partingoperation has been performed. Accordingly, the spacingof the parts willnot in all instances be exactly as shown in the illustrations, since anumber of variable elements are involved, such as width of the finishedflange, ductility of the metal, and sharpness of contour of the edgefollowed by the flange.

Where the flanges are not sharply contoured or curved, and. where theyare formed along straight edges, raised restraining members, such as themembers 40 and 4| need not be employed, but the surface of thesupporting plate 5| may serve as a suitable restraining means, As shownin Fig. 6, the projecting edge 6| of the sheet 80 is forced by thematerial 55 into engagementwith the upper face 15 of the supportingplate 5| at a point spaced from the butting blade 48. The interveningportion 15 of the sheet,,between the shoulder 36 and the point ofengagement with the surface 15, will be caused to flow as it is movedtoward the cutting edge 48. Accordingly, if the curvature of the sideface 33 of the forming block '22 is not large the metal entering intothe flange which is to be formed against the side face 33 may be drawnsufficiently to prevent wrinkling at the gripping of the extreme edge ofthe sheet 60 against the upper face 15 of the supporting plate 5|.engagement of the projecting edge 6| of the sheet 60 with the surface 15of the plate 5| may be increased, the surface 15 may be provided withbeads or ribs, or several grooves 28 may be cut in the surface 15, asshown in Figs. 2 and 6.

Where selected parts or corners of an article, such as the article I ofFig. 1, are to be formed with cutouts 80 between the ends of the flangesI1 and I8, L-shaped trimming knives 8| may be recessed into the corners82 of the forming block, these corner knives being made as shown in Fig.7 and having sharp edges 83 to cause the cutting of the excess metaladjacent the corners 82 from the portions of the sheet entering into theflanges I3 and I1. The corner knives 8| each have a pair of wings 85disposedsubstantially at right angles and being connected by a curvedportion 86. The wings 85 slope downwardly and outwardly so that the sideportions 81 of the cutting edge 83 will slope downwardly and outwardlyfrom the upper curved portion 88 of the cutting edge 83, which uppercurved portion 88 of the cutting edge 88 is preferably level with theupper face 23 of the forming block 82.

The form of the invention disclosed in the foregoing may be employed forthe drawing of reasonably deep flange portions around contoured externalportions of a forming block and also within the openings of formingblocks. Where greater depth of draw or flow of the metal is required,beyond the extent obtainable by use of the foregoing form of theinvention, a step by step drawing or flowing combined with a step bystep cutting of portions of the metal may be employed in the mannertaught in Figs. 8, 10, and 11. In Fig. 9 I show a part 90 which has beenformed by use of a forming block 8| in a press such as illustrated bythe parts 53, and 55 of Fig. 3. In Fig. 11 a characteristic portion ofthe part 80 is shown to enlarged scale upon that portion of the formingblock 8| on which it has been formed. The part 80 comprises a top wallportion 82 having an opening 83. therein deflned by a wall or flange 84which slopes downward and inward and ends in a bead 85. The outerportion So that the restraining effect of the of the top wall is Joinedthrough a sloping wall portion88 with an outer wall portion 81 in aplane downwardly offset from the top wall 82. From the edge of the wallportion 81 a flange 80 extends downward. The forming block 8| has aforming body 88 with faces 82a, 84a, 88a, 81a, and 88a corresponding inposition and form to the portions 82, 84, 88, 81, and 88 of the formedpart 80. This forming body 88 lies in circumscribing relation to anopening or recess I00, lying within and formed in part by the inwardlydisposed sloping face 94a. A flow controlling or restraining means IOIis placed in operative relation adjacent the forming member 88, and inparticular within the opening or recess I00 of the forming block 8|.This restraining means |0| has cooperating means for producing aconsecutive step by step movement of the portion of the metal sheetwhich enters into the formation of the flange 84 and the bead 85, at alltimes maintaining such restraint and control of this portion of themetal sheet that the relatively deep flange may be drawn in a singlesubstantially continuous operation. The control means |0I comprises aseries of separate restraining elements I02, I03, and I04, each having aparting means I020, I03a, and I 04a associated therewith. Therestraining means I02, I03, and I04 comprise consecutive stepsprogressing upwardly and away from the inner edge of the channel shapedface 95a, the number of these steps employed being determined by anumber of different factors including the depth of draw of the flange84. The steps I02, I03, and I04 may be formed by mounting steel platesI05, I01, and I08, of similar peripheral form but of gradually decreasedarea, in spaced relation, so that the upper plate I 08 will lie in ornear the plane of the upper face 82a and the lower plate I06 will lie ina plane at or slightly above the inner edge of the channel shaped face851:. The plate I08 may be supported upon a portion I08 of the formingblock 8| and the plates I01 and I08 may be respectively carried onsuitable filler pieces 0 and III formed from any suitably strong or hardmaterial, such as Masonite. In the form of the invention shown the upperstep I04 comprises the upper face of the plate I08, but the steps I03and I02 consist only of the projecting peripheral portions of the platesI01 and I08. The parting means I02a, I03a, and I04a consist of sharpedges formed around the peripheries of the plates I06, I01, and I08.

A knife edge H2 is provided adjacent and below the outer face 98a by useof a steel plate 3 which lies in part under the forming body 89 and hasa diagonally upwardly projecting lip 4 on which the severing or partingedge I I2 is formed. The plate II3 need not extend entirely across theunder face of the forming block 8| and a filler plate II5 of a cheap butsuitably strong material may be placed adjacent that portion of thelower face of the forming block 8| not covered by the plate I I3.

Forming of the part 80 by use of the forming block 8| is conducted inthe following manner. A sheet 20 of suitable material, such asduralumin, for example, is placed across the top face of the formingblock 8|, and a body of yieldable material, such as the body 55 of Fig.3, is brought downward under pressure against the upper face of thesheet I20. The first action of this body of yieldable material is toforce the sheet into tight engagement with the face 82a of the formingmember 88 and with the step I04. As pressure Is increased in theyieldable material the peripheral portion I2I of the sheet I20 will beforced down toward or into a position such as indicated by dotted linesI2Ia. The portion I22 of the sheet I20 which projects from the face 92ato the step I04 will be forced downward in the channel or space betweenthe shoulder I23 and the cutting edge I04a' of the step I04, this, asindicated by dotted lines I22a. This will result in a drawing andflowing of the sheet portion I22 so that it will becarried partly aroundthe shoulder I23, and at or about the time the portion I22 reaches theposition indicated by dotted lines I22a, the sheet I20 will part alongthe cutting edge M411 and the portion of the sheet which may be referredto by the numeral I22a will then drop down so that the edge portion I24thereof engages the step I03, leaving a plate I25 of scrap or salvageresting on the step I04. The release of the inner edge of the sheetportion I22b when it is severed from the edge I26 of the plate I25,permits the sheet portion I22b to move downward and also toward the face94a, with the resultthat there is a definite flowing of metal in thesheet portion I221). accompanied by an expansion of the edge portion I24thereof which makes engagement with the step I03. There may or may notbe some movement of the edge of the sheet portion I22b after it isforced into engagement with the step I03.

As the pressure is increased in the body of elastic or yieldable andconformable material,

shoulder I23 or side face 940 of the forming body. In each form of theinvention the edge portion of the projecting sheet is restrained so thatthere will be a flowing of the metal as the projecting portion movestoward the side face of the forming block, and then a part of theprojecting sheet portion in which working and crystallization of themetal has occurred, is severed from that part of the projecting sheetportion which contains the metal which is to enter into the formation ofa contoured flange.

I claim as my invention:

1. In a device to draw, form, and cut an article from sheet metal foruse between a support and a body of yieldable material which is movedtoward said support under such pressure as to be caused to conform tothe exterior of. an object on said support, the combination of: aforming block on said support, said forming block having a top face anda side face joined to said top face by a shoulder; a restraining blockspaced from said forming block, said restraining block having a top faceand a side face, said side face of said restraining block being spacedfrom said side face tension exerted in the sheet portion I22b causes 7 aparting of the same along the cutting edge I03a leaving the edge portionI24 thereof resting upon the step I03 while the remainder I22c of thesheet portion I22b is moved downward and further toward the face 94a,the edge portion I20 of this remaining sheet portion I22c being forcedinto engagement with the step I02, to restrain such edge portion I20 asthe sheet is drawn and worked downward toward the face 95a, this beingfollowed by a parting of the sheet portion I220 at the cutting edgeI02a, leaving the edge portion I28 thereof lying upon the step I02 andpermitting the flange and the bead portions of the sheet, respectively94 and 95, to be forced under heavy pressure against the faces 94a and05a, as shown in full lines.

At some time during the above described consecutive steps of drawing andcutting the sheet portion I22, the projecting sheet portion I2I will 9to 11 embraces the characteristics describedrelative to Figs. 1' to 6inclusive, but enlarges upon the same. For example, each step I02, I03,and I04 has a cutting edge associated therewith, which cutting edge isdisposed between the restraining means formed by each step and theshoulder I23 and/or the face 94a. Although the cutting edges I02a, I03a,and mm are formed by the plates I06, I01, and I08 which likewise formthe steps I02, I03, and I04, it is the upwardly presented faces of thesesteps that comprise the respective restraining means, and, accordingly,it may be properly said that the parting means formed by the cuttingedges are disposed between the restraining means and the of said formingblock so that a recess is formed between said faces into which a portionof the sheet may be forced by, said material; and parting meanspositioned in said recess between and in spaced relation to said formingblock and said restraining block and located below a line connecting theshoulders of said blocks, and at a place to engage a portion of thesheet metal which has been forced into said recess, before the formingoperation of said portion of said sheet metal has been completed,whereby said parting means serves to remove the severely worked portionof the metal lying between said parting means and said restrainingblock.

2. In a device to draw, form, and cut an article from sheet metal, foruse between a support and a body of yieldable material which is movedtoward said support under such pressure as to be caused to conform tothe exterior of an object on said support, the combination of: a formingblock having a top face and a side ,face; and a stepped restrainingmeans lying to the side of said block, said restraining means having aplurality of steps consecutively downwardly and toward said block, eachof said steps having an upper face to receive portions of the sheetduring the forming operation and having parting means associatedtherewith so that portions will be cut from said sheet as the drawingand forming operation progresses.

3. In a device to draw, form, and cut an article from sheet metal, foruse between a support and a body of yieldable material which is movabletoward said support under such pressure as to be caused to conform tothe exterior of an object on said support, the combination of a formingblock having a top face and a side face; and a stepped restraining meanslying to the side of said block, said restraining means having aplurali'ty of steps consecutively downwardly and toward said block, eachof said steps having an upper face to receive portions of the sheetduring the forming operationland having a relatively sharp partingShoulder at the edge thereof so that portions will be cut from saidsheet as the drawing and forming operation progresses.

4. In a device to draw, form, and cut an article from sheet metal, foruse between a support and a body of yieldable material which is movabletoward said support under such pressure as to be caused to conform tothe exterior of an object offset consecutively downwardly and towardsaid block, each of said steps having an upper face to receive portionsof the sheet during the forming operation and having parting meansassociated therewith so that portions will be out from said sheet as thedrawing and forming oper tion 10 progresses; and means forming a channelbetween said side face of said forming block and the lowest of saidparting means.

5. In a method of forming a flanged article from sheet material bydrawing, cutting and shaping the sheet, the steps of: applying ayieldable material to said sheet, to hold same against a forming blockand a restraining surface spaced from said forming block to provide aspace into which a portion of said sheet may be forced;

applying additional pressure to said yieldable material so as to force aportion of said sheet into, said'space to form this part of said sheetinto a U-shape; cutting said sheet along a line within said space andseparated from said forming block and restraining surface but closer tosaid forming block to remove a greater portion of the U- shaped part ofsaid sheet in said space; and continuing the application of pressure bysaid yieldable material to move the remaining portion of said sheet insaid space toward said forming block to complete the forming operation.

6. In a method of forming a flanged article from a sheet by drawing,cutting, and shaping the same in a substantially continuous operationover a forming block having a top face and a side face, the steps of:applying a body of yieldable material to the sheet to force it againstthe forming block; increasing the pressure in said material so that aportion of said sheet projecting 40 from the top face of said formingblock will be deflected downward; restraining said projecting portion ofsaid sheet at a restraining surface spaced from said forming block sothat it will flow as it is forced downward into said space toward saidside face of said block; severing a portion of said projecting portionof said sheet from the remainder of said projecting portion of saidsheet at a location within said space between said forming block andsaid restraining block and separated from said forming block and saidrestraining surface in such a manner to remove from said projectingportion of said sheet the most severely worked part thereof; andcontinuing the applicationof pressure in said material to move saidremainder of said projecting portion of said sheet into fully formedposition.

7. In a method of forming a flanged article from a sheet by drawing,cutting, and shaping the same in a substantially continuous operationover a forming block having a top face and a side face, the steps of:applying a body of yieldable material to the sheet to force it againstthe forming block while restraining said projecting portion of saidsheet at a place spaced from said forming block so that it will flow asit is forced downward into said space toward said side face of saidblock; severing a portion of said projecting portion of said sheet fromthe remainder of said projecting portion of said sheet; continuing theapplication of pressure in said material to move further toward saidside face of said block said remainder of said projecting portion ofsaid sheet; restraining and severing in said space an additional part ofsaid projecting portion of said sheet from said remainder; and bypressure applied through said material moving the residual part of saidremainder toward said forming block.

8. In a device to draw, form, and cut an article from sheet metal foruse between a support and a body of yieldable material which is movedtoward said support under such pressure as to be caused to conform tothe exterior of an object on said support, the combination of a formingblock on said support, said forming block having a top face and a sideface; a restraining surface spaced from said forming block in such amanner that a recess is formed between said forming block and saidrestraining surface into which a portion of the sheet metal may beforced by said material; and parting means positioned in said recessbetween and in spaced relation to said forming block and saidrestraining surface and located below a line connecting said restrainingsurface and the top face of said forming block, and at a place to engagea portion of the sheet metal which has been forced into said recess,after said portion has been partly formed and before the formingoperation on said portion of said sheet metal has been completed,whereby said parting means serves to remove the severely worked portionof the metal lyin adjacent said restraining surface.

CHARLES C. MISFELDT.

